If the offshore wind turbines are too numerous, they will produce less power; this should be considered when planning the farms
HELMHOLTZ-ZENTRUM HEREON
The expansion of wind energy in the German Bight and the Baltic Sea has accelerated enormously in recent years. The first systems went into operation in 2008. Today, wind turbines with an output of around 8,000 megawatts rotate in German waters, which corresponds to around eight nuclear power plants. But space is limited. For this reason, wind farms are sometimes built very close to one another. A team led by Dr. Naveed Akhtar from Helmholtz Zentrum Hereon has found that wind speeds at the downstream windfarm are significantly slowed down. As the researchers now write in the journal Nature Scientific Reports, this braking effect results in astonishingly large-scale low wind pattern noticeable in mean wind speeds. On average, they extend 35 to 40 kilometers – in certain weather conditions even up to 100 kilometers. The output of a neighboring wind farm can thus be reduced by 20 to 25 percent, which ultimately leads to economic consequences. If wind farms are planned close together, this wake effects need to be considered in the future.Combination of climate and wind farm data
With their study, Naveed Akhtar, an expert in regional climate modeling, and his colleagues took a look into the future and assessed the wind characteristics for a medium-term target state of offshore expansion. They used the computer model COSMO-CLM, which is also used by weather services and which is able to resolve weather situations regionally in detail – in this case for the entire North Sea and combined it with the future wind farm characteristic – their area and the number and size of the turbines. They used the wind farm planning for the North Sea from 2015 as a basis. This contains wind farms, some of which have not yet been built.Braking effect especially in stable weather conditions
Naveed Akhtar used the COSMO model to calculate the wind speed over the North Sea for the period from 2008 to 2017 covering a range of different weather conditions. The results clearly show that we will face a large scale pattern of reduced wind speed, which show largest extensions during stable weather conditions, typically the case in March and April. In stormy times, on the other hand – especially in November and December – the atmosphere is so mixed that the wind farm wake effects are relatively small. In order to verify the model data, the team compared the simulations with wind measurements from 2008 to 2017. They used measurements that were recorded on two research platforms in the North Sea and data from wind measurement flights that colleagues from the TU Braunschweig performed over existing wind farms. The comparison shows that the Hereon researchers are correctly simulating the wind wakes. What is special about the work is that for the first time a full ten-year period has been calculated for the entire North Sea. “Conventional flow models for analyzing wind farms have a very high spatial resolution, but only look at a wind field over a short period of time,” says Akhtar. “In addition, these cannot be used to determine how a wind farm changes the air flow over a large area.”
While the group has mainly dealt with the extent to which the wind farms influence each other in their current work, they intend to investigate in the near future what influence the reduced wind speeds have on life in the sea. Wind and waves mix the sea. This changes the salt and oxygen content of the water, its temperature and the amount of nutrients in certain water depths. Naveed Akhtar: “We would now like to find out how the reduced mixing affects the marine ecosystem.”
###
Thus we discover the Law of Diminishing Returns.
How very novel.
Could be Peak Wind
Bryan,
It could be “down-wind” from here on
Winded?
that blows
You guys completely took the wind out of my sails and thrown me fully aback.
Sounds like junk. There has been a lot of work published on interference, see here. It’s a normal part of wind farm design. Of course they need spacing.
And huge areas of sea or land to put the stupid bird choppers on.
Chaswarbertoo, that is what I call them too, bird shredders.
Sound what you’re admitting is models are junk, yes?
It does sound like junk. Why all the downvotes?
He calls it junk, but doesn’t back it up with evidence that it is junk, thus the down votes.
Ok, just trying to be fair. By all means, down votes are appropriate whenever Nick shucks and jives his way through the substantial failings of the GCM’s. However, in this instance, he simply stated that the subject research was bogus, which it is, and then provided a link to a number of sources that indicate turbine spacing is not an unknown issue in wind farm design.
His link goes to a article list on Google Scholar, which means he still doesn’t address this ARTICLE itself at all.
Not going to run around to find what his objection is about in Google Scholar, he needs to post them here in some detail what it is he objects to.
He should do better than that.
Nobody ever claimed that the issue of spacing is an unknown issue.
The issue is the claim that this study must be junk because it differs from other studies.
Beyond that, the listed studies deal with spacing between windmills, while this one deals with the spacing between windmill farms.
Yes, turbine spacing is, of course, a factor in wind farm design. But the article is pointing out that there is interference between wind farms, many km apart. Gee, if you suck energy out of the atmosphere here, there will be less available downwind. DUH.
When the wind farms become wind turbine regions, the down wind half of the wind region becomes under performing, which call into question their existence at all because wind farms operate at way less than 100% most of the time. Losing another 20–25% is a major blow. Perhaps an array of half the size would be better. No need to build the other half.
Charles,
And forfeit all these subsidies? No way!
That can be offset by proportionally increasing subsidies to the oppressed downwind turbine regions. Or, by wind equity distribution regulation, which requires upwind turbine regions to periodically shut down, until oppressed turbine regions achieve parity. Easy peasy, nice and easy…
Anon, most brilliant observation. New Lawfare, wind discrimination.
Surely that’s the wrong way round. There should be less subsidy to a windfarm that’s downwind of another, because it will produce less. Actually, since the wind direction can change, both windfarms should receive less subsidy. Thinking a little further, any windfarm with more than one row of turbines should be given less subsidy, just as it would if the second row onwards belonged to a different windfarm. Seriously, the easiest solution is to accept the windfarm operators’ assertions that their energy is now the cheapest, and just end all subsidies.
I think the wind turbines are a waste of resources, but if we have to have them this and other research shows or hints that huge single turbines far apart might be better than a herd of smaller ones. Love the idea of floating turbines in the jet stream. One heck of an extension cord, though. Wonder if microwave beamed energy would be viable in this case, like what was proposed for solar power satellites.
I don’t quite understand why you call it “junk.” If you actually look at all of the studies to which you linked, they show the same phenomena. I know, because I’ve been looking at it for years. The main thrust of prior research has been on optimal wind turbine spacing, which is what motivated the current study – but this paper goes on to look at environmental impacts. And I don’t mean chopping up birds and bats, but subtler aspects that may well be large. After all, the wind is the transport mechanism for heat, water, biological materials, and minerals – all of the things that control climate and life itself. And we wish to interrupt that mechanism to get some unreliable energy at truly stunning cost. What could go wrong?
Well, these researchers have realized, from their analysis and measurements, that a few things could go wrong. They propose looking at some of them.
What most of the references which your search contains conclude is that optimal wind turbine spacing is much larger than has been used in practice. It should be on the order of 10 to 15 rotor diameters between hubs. This has the effect of reducing wind power density from about 3 W/m^2 to about 0.7 W/m^2. Replacing the 1 TW capacity of US power plants would thus require about 1.4E6 km^2 of territory, whether on land or water (15% of the area of the United States). And that couldn’t have any negative environmental impact, now could it…
‘I don’t quite understand why you call it “junk.” ‘
Maybe not the right word. But when the Eureka puff has stuff like
” If wind farms are planned close together, this wake effects need to be considered in the future.”
then it isn’t promising. Wake effects are considered now, as a routine part of wind farm design.
Nick – it’s all a matter of scale. The wake effects used up until now are obviously fairly good for low speed, minimal effect calculations. However the authors appear to have taken those calculations as a starting point and modelled them for different wind strengths up to, presumably, near maximum operating speed. Knowledge often advances more quickly from making mistakes than getting things right straight away. So, now we have a much better understanding of how wind farms operate collectively at different wind strengths and can space the turbines out in a much more efficient manner to maximise the energy output. What’s the problem with that?
Just because wake effects are considered, is not evidence that they are being considered correctly.
Many people add links to other sources in their posts. Multiple posts here refer to Nick’s links. Why can’t I see any links in his post? What am I missing?
Yes,as a layman I have concerns. Perhaps not now, but could so many windfarms be built that they alter the traditional wind patterns that allow life on the planet to exist?
Wind turbines convert the kinetic energy of moving air into heat. Nearly all that heat is dissipated at or near the surface by electric lights, motors, etc. By slowing surface wind, wind turbines also reduce natural convection, which reduces heat removal from the surface, which causes still more warming.
“Wind turbines convert the kinetic energy of moving air into heat.”
Well, that isn’t the aim. They seek to convert translational energy from the wind to rotational energy of the blade. They do this by deflecting the onflow, transferring momentum to the blade. A major loss is the energy used in shedding vortices.
The blades turn the generator, which makes electricity and heat, then the electricity gets transmitted to end users who convert it to heat. Eventually, all the electricity gets converted to heat. Plus the heat from friction on the blades and the shedding vortices, and turbines reduce wind speed, which warms the surface. They should call them global warming machines.
“Big whirls have little whirls,That feed on their velocity;And little whirls have lesser whirls,And so on to viscosity.”
All the kinetic energy of the wind will degrade to heat, with or without wind farms.
Like the heat from thermal power plants, the heat from wind turbines, and the heat from use of their electrical output, is so tiny compared to the heat produced by incoming solar that, except in very limited immediately near areas, it can’t even be rationally calculated.
The aim is irrelevant.
What matters is what actually happens.
Wind turbines do turn.
Nobody ever said the didn’t.
Why can’t you ever respond to the actual point made instead of trying to divert the discussion off into irrelvancies?
Stokes defense activated … must mislead and misdirect for the cause.
And crash and burn
As usual, Nick can’t actually refute anything in the study, he just declares it to be junk because it doesn’t support the position he’s paid to support.
It was worse than we thought!!
Why is this a surprise? Where do they think the energy comes from!
I think they have just stumbled upon the conservation of energy. I’m going to be wryly amused if they plaster the west coast of the US with off-shore wind farms, then wonder why they no longer get beneficial Pacific storms moving inland with much needed rain.
Evening winds that cool during summer nights are very important to life on the west coast.
They can use the first wind farm to power fans to make the second wind farm run better.
Well shouldn’t affect the additional 30GW of UK offshore wind coming in the next 10 years (much of it in the next 5)
Every crook in Britain seems to be getting into offshore wind these days. Why not if there are massive subsidies to be gobbled up. Unfortunately, these subsidies are all going on to everybody’s electricity bill. It’s about time that “green” subsidies were separately itemised on power bills so that people can see how much they are paying for this pointless virtue signalling.
Too much scary reality for that to happen. If you actually understood how much money is going into that area, there’d be a revolt.
Those who “believe” in anthropogenic warming should be held responsible for these extra costs. Those of us who know it’s a scam should be exempt. Tat way we’ll know how many want their taxes to go to directly into the pockets of the subsidy farmers.
Why shouldn’t it? Are these windmills being put in a place without wind?
When they actually generate 30GW wake us.
Windmills in UK are magical, they can get power from the air, without taking energy out of the wind.
When I hit this line,”Today, wind turbines with an output of around 8,000 megawatts rotate in German waters, which corresponds to around eight nuclear power plants.” I just stopped. Did this come from The Onion or The Babylon Bee?
As usual, wind power apologists don’t know the difference between capacity and output.
Wind speed nearly always drops 50 to 100 percent at night.
http://www.usairnet.com/cgi-bin/launch/code.cgi?state=WI&sta=KMWC
I doubt that my local air strip is unusual in that regard.
It depends on location. Here, sundown and after is when the winds are (most frequently) most noticeable.
If you follow the link:
http://www.usairnet.com/cgi-bin/launch/code.cgi?state=WI&sta=KMWC
you can select your state and an airport near you to see if what you said is true. Yes when the sun goes down there’s often a stirring of the air that is noticeable, but does it continue all night long?
I checked a few states, CA, TX, TN, FL, CO, ID, AZ, NY and what I said is generally true.
Where are you that you think the wind blows more at night?
Air flow off the ocean into San Francisco Bay, into the delta, up the river. Not every night but perhaps 25% to 35% of the time. when it doesn’t blow, temperatures rise or at least stay high and stifling day after day. come the breezes, clear out a lot of hot for a few days, then the cycle starts over. This is very noticeable, not the least bit subtle.
Wind power is just fine, for sailboats and kites. For a high energy advanced technology society? Not so much.
Beware the doldrums.
And the DrollDumbs
Quite true. But on the positive side, at least they’re referencing SI units, rather than the usual Alarmist junk units like “Hiroshimas” or “small cities”, etc.
So now the Germans are mis-deploying their turbines in the same waters they mis-deployed their fleet in 1916?
Learning from history, not really the German people’s strong suite.
Eight nuclear power plants that occasionally operate.
Very occasionally, like the times Smitty McGrump the janitor remembers to hit the on switch! 😉
yep you have to build eight “nuclear power plants” worth to get two nuclear plants ~50% of the time and hope that you can get at least one nuclear plant ~95% of the time
but on rare occasions the wind blows hard all over (but not TOO hard) you get another several “nuclear power plants” online with no real demand for them so then you have to shut a lot of it down anyway and/or shut down other power sources that are operating more efficiently/consistenly
and on the not so rare conditions the wind doesn’t blow enough you have to hope neighbors are generous enough to fill in the gaps at exorbitant prices or build enough standby fossil fuel infrastructure to step in
Wind farms convert kinetic energy into (ultimately) heat. Presumably they reduce advection and its resulting horizontal heat transport. Not a free lunch.
I’m waiting for the low rev turbines anchored in the gulf stream off the Florida coast. These beauties will put Europe into a deep freeze while lighting the east coast. Yeah!
Wind is movement of the atmosphere from higher pressure to lower pressure, modified by the Coriolis effect. Irregular surface features slow down the wind and the Coriolis effect changes the direction of the slower wind. This effect could easily be determined for prevailing wind direction and speed and the wind turbines located to experience the least disturbance. The notion that winds display turbulence 100 kilometers downwind from a wind turbine is modeled nonsense. The real problem with wind turbines is that they are not carbon neutral and they chop up our flying friends, and those in ocean waters are hazards to navigation. Go Nuclear.
Plus, windmills are ugly.
And they have a noise that causes mental problems 100 kilometers away.
Not what I have read, Mr Long. Those know effects are around one statutory mile.
So windmills are Leftist?
That’s pretty much the size of it.
Yes, both windmills and Leftists are delusional.
So many aspects in here..
1) We’re in among ‘wind-break’ or ‘wind-shelters’ and anyone who has ever kept livestock in ‘less than ideal climate situations’ will know about
1a) Obviously, behind the windbreak, there is shelter from the wind. General rule of thumb being for a distance of ten times the height of the wind-break
1b) There is also shlter in front of the wind-break – general thumb saying= a distance of twice the height of the wind-break
Wind Is Not Dumb – it sees the wind-break ‘thing’ coming – and starts avoiding action well before it gets there
2) Put yourself in the position of The Wind and apart from seeing the thing coming, what you see and not intuitive with big 3-bladed or any# blade mills, what you see is a completely solid circle.
Not big empty spaces between the blades that we see.
Enough of that but in view of it- what about comparing windmills to trees.
Trees and hedges (wannabe trees) being the very things that folks use as windbreaks.
OK
These folks tell us that windmills and thus trees, affect the local and not-so local wind-speed.
This surely Shirley CAN NOT affect Climate, because Climate = Temperature as we all know. An alteration in wind-speed could have no climatological effect
Tell you what, lets be ‘Little Devils’ or avocados thereof, put away the whiskey wine and doughnuts for a minute and Engage Brain. Got that Spock?,now Make It So
Warp 3 or 4 will be way waaaaaay plenty, this is not an exercise in self-pleasurement.
Thus, if you have a dense assemblage of windmills, as here, wind speed on the ground decreases. Maybe that might affect ‘other things’ – such as the rate of evaporation of water not least? How might that affect temperature?
Thus, lots of windmills = calm and not many = windy
How might if affect things growing on the ground, plants and TREES for example?
Would calm mean less water loss from the plants and soils?
So…..
If lots of trees, then damp soil and moisture filled plants
If not many trees and thus windy = dry soil and water-stressed plants, possibly prone to ‘catching fire’?
Now, lets take all this to sunny Calli-Forn-IA and introduce ourselves to Saint Ana
I’ll let you work it out, especially those who think that burning holes in an existing ‘forest’ is a Good Way to save it – from burning
Before you chow down your next donut thereby closing your eyes ears and mind, think about it – maybe ‘something else’, something other than burning it, might ‘save the forest’
sigh
and you know me, 😀
…….this applies to everything that might possibly be described as Biomass, Biofuel Bio-blah-blah. Show Ma nature a bit of respect, huh
Wonder if the might be a Global Aspect to that – what say you Shirley?
Be careful Shirley, let’s not bring back comon sense, we have GoogleWicki….
Cheers
Mike
Any (racing) yachtsman will understand the effect of wind turbulence from yachts ahead and adjacent them … the effect of turbulence is substantial for quite some distance to lee’d. Get into the wrong position on the start line and the fleet turbulence will really screw you.
Wind turbines are much bigger and effectively can present an apparent ‘solid’ barrier to wind.
Just sayin’.
I’ve spent a fair amount of time hiking and exploring in the mountains. Conditions differ from place to place but I’ve seen ponderosa pine and other fir tree seedlings coming up like a carpet of grass more than a few times. A friend who lives on a few acres supporting a variety of oaks says she has often seen oak seedlings growing the same way. None of the trees in such a “planting” are likely to ever amount to much. I’ve also seen many places with stunted trees twisted and crowed to such a extent that one cannot get through.
On the other hand the forest service has done great work in some areas. The trees are well spaced, there are occasional thickets of bushes but there is much open room for humans to walk and animals to graze or find other food. Humans are capable of doing better than “Ma nature” (not to claim that they frequently do). Unfortunately such areas are rare and not terribly extensive. Costs are too high.
Burning is often a waste of resources but quite a few trees and other plants have evolved to do much better in areas that get burned off every once in a while. Controlled burning has been well proven to improve the areas burned, as least in many kinds of environment, from prairie to redwood forests.
Evidence seems to support that the people who were here for 10,000 years or more before Europeans came were not doing too badly by frequent burning. That figure could be 50,000 to 60,000 years in Australia from what I’ve read.
The ideal practice might be to use what can be used for constructive purposes and to compost the rest. When composed to near the condition of soil, and mixed with a little mineral rich sub soil, the product would do the forest soil great good if spread over the forest floor often enough. In that condition it is unlikely to present much of a fire danger, especially in combination with the fire preventive practice of rational thinning.
The overwhelming problem with the concept is the labor and energy cost it would require. Controlled burning at least returns most of the minerals to the soil, in addition to its other benefits.
Sounds to me like they’re gearing up to say “wind power bad” now, which will leave us only solar until they discover that PV panels contribute to the UHI effect. Therefore, all power is bad. Back to the stone age!
So you’re seeing that down the road, only a short way, it will be, “No nuclear, no fossil fuels, no wind, no solar, no hydro, no wood…”?
The good news is everything poops, so we can all use dung for cooking and heating.
Always look for the silver lining, Right-Handed Shark.
😜
Maybe they are slowing the earth’s rotation?
No. Conservation of Momentum.
Earths rotation is slowing anyhow that has been known for centuries … we have to adjust time for it
https://en.wikipedia.org/wiki/Leap_second
Are wind farms slowing each other down?
Good news for birds and bats if they are.
I much preferred the old names like Heligoland (now German Bight) and Finisterre (now FitzRoy) etc
This is the most informative image ever taken showing the effects of turbine disrupting laminar flow and the effect on downstream system.
From https://www.windpowermonthly.com/article/1457746/dtu-vattenfall-partner-shadow-effect-project
It will aid planning of future offshore sites
It won’t reduce the madness.
While this picture is from the real world, there is no reason why the down wind effects couldn’t be studied in a wind tunnel. Old fashioned, I know, but you can get the same kind of picture. And I assert that one picture is worth a thousand lines of computer printout.
That would take a very large wind tunnel to get the scale effects right, and minimize the wall effects.
So wind turbines follow the law of conservation of energy? Who woulda thunk it? Maybe solar panels do also. Maybe they are what’s raising the Earth’s temperature to the dangerously high 1.5 degree level and it’s not CO2.
Much worse. They directly influence the climate.
They do slow down the global winds and change the climate patterns.
“. . . they intend to investigate in the near future what influence the reduced wind speeds have on life in the sea. Wind and waves mix the sea. This changes the salt and oxygen content of the water, its temperature and the amount of nutrients in certain water depths. Naveed Akhtar: “We would now like to find out how the reduced mixing affects the marine ecosystem.”
I’m betting on beneficial.
I’d bet large on lower wind speeds that would generate less waves and mixing, causing detrimental effects. The places most teeming of sea life are places where there’s lots of mixing and upwelling, and the quietest and calmest are the deadest.
When will all these models predict the wind turbines will reverse the earth’s rotation? Not far away I’m sure.
Of all the problems wind power has, they want to focus on that.
M’kay.
Anyone who has been on a sailboat knows what happens in a wind shadow.
https://www.pnas.org/content/101/46/16115
I’m waiting for the claim that wind turbines are slowing (or speeding up) the rotation of the Earth.
Or perhaps, a claim that wind turbines off from the equator are twisting the rotation.
Well, this may be bad news or Chevron Executives whose pay is now tied to reducing emissions?
So harvesting all this wind energy will have no effect on climate?
Of course not. “Greene” energy is pure and free. (as in beer)
“A team led by Dr. Naveed Akhtar from Helmholtz Zentrum Hereon has found that wind speeds at the downstream windfarm are significantly slowed down.”
They just now figured this out? It should be obvious to anyone with a high-school understanding of physics.
If they are going to rely on windmills maybe a redesign might work better. Or maybe coal and gas might work as well. Along with nuked power.
There are a number of designs, some coming on the market, that significantly reduce certain problems. Of course the wind will still not blow evenly or always when needed.
Folks, what is being described is known as the Betz Effect. See Wiki under that call-out; it has a short but OK description…
North shore of Boston three turbines were installed to close to each other
now when the wind blow from several directions two of them have to be shut down due to turbulence
This is a very simply put question — Wind is an important aspect of evaporative cooling … if you take energy out of the wind and it reduces general wind velocity, what is the impact on evaporative cooling ? What is the implication for warming of the planet ?
Nice to have some data, but DUH. This just now occurring to the intelligentsia?
They’ll have to build them at staggered heights then.
There is a given amount of energy in wind in a localized area. Each working windmill removes a given amount. So there is less for other windmills.
Wind farms do pull energy out of the wind, it isn’t free energy, it reduces what remains. Do you reach a point where weather no longer functions?
I’d be more interested in a theory that asked, if one wind turbine caught on fire, would that fire spread and destroy it’s neighboring wind turbines? And in a perfect world, the answer would be yes, and all the bird and bat choppers would have burned up by now.
Cheer yourself up with a good wind turbine fire video:
If wind farms change weather patterns and air flow, they can change temperature. Where are the trial lawyers? That theory is easily provable.
Re: energy output from wind farms:
It’s worse than we thought!
Give the continuous improvement in wind turbine technology and control, is even a 25% loss in “output”, from a worst case assignment of the location of the next wind farm that big of a deal?
The oilfield equivalent is increased drilling density. A 25% decrease in /well ultimate recovery from the next campaign of infill drilling/completions would not cause even a twinge of doubt in the eyes of most operators. Shale operators, for example are seeing diminishing returns much worse than this, but are still TRYING to infill, in spite of the Money finally wising up to the realities of competitive drainage and frac hits. Even if the worst case proves true, wind site candidate quality has degraded a tiny fraction of that of the shale drillers.
Since your given is absurd, your conclusion based on the given is nonsensical.
Where is this big increase in windmill efficiency that your fevered imagination dreams of?